1. Field of the Invention
The present invention relates to a resonant effect apparatus adapted for use in electronic musical instruments, and more particularly to a resonant effect apparatus for electrically providing resonant effects caused by a plurality of resonant elements such as piano strings.
2. Description of the Prior Art
In Japanese Patent Early Publication No. 63-267999, there has been proposed a resonant effect apparatus of this kind which includes a plurality of resonant tone signal forming circuits each composed of a comb filter different in resonant frequency characteristics. In the resonant tone signal forming circuits, a plurality of resonant tone signals are formed in response to an input musical tone signal and mixed to be sounded from one or plural loudspeakers for electrically providing resonant effects caused by oscillation of plural strings as in a piano.
In a natural musical instrument such as a piano, a plurality of strings are aligned to resonate when one of the strings has been sounded by depression of a key. Thus, the resonant tones of the piano strings are sounded at different positions to effect spatial broadness in a musical tone. In such a conventional resonant effect apparatus as described above, however, a plurality of different resonant tone signals are applied to one loudspeaker to be sounded therefrom. For this reason, a musical tone applied with the resonant effects sounds unnatural due to lack of spatial broadness. In the conventional apparatus, the musical tone signals from the musical tone signal forming circuits are applied in common to each of the resonant tone signal forming circuits. Accordingly, the resonant tone signal forming circuits are applied with the musical tone signals at the same volume level irrespectively of the tone pitch thereof. This means that in the piano the oscillation of the sounded string affects the same influence to the resonance strings, irrespectively of the distance between the sounded string and the resonance strings. In this sense, the resonant tone obtained in the conventional apparatus becomes unnatural.